Mast Cell Activation Syndrome (MCAS)

Cancer Care</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/digestive-health">Digestive Health</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/mental-health">Mental Health</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/psoriasis">Psoriasis</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/weight-management">Weight Management</a></li></ul></div><div><h3>Condition Spotlight</h3><a class="css-p98bl6" href="/cats-d8c4vu/www.healthline.com/program/navigating-life-with-bipolar-disorder"><div class="css-10adefi"><div class="css-88ot4l"><img loading="lazy" src="/cats-d8c4vu/www.healthline.com/program/managing-type-2-diabetes-with-food-and-fitness"><div class="css-10adefi"><div class="css-88ot4l"><img loading="lazy" src="/cats-d8c4vu/www.healthline.com/fitness">Fitness</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/nutrition">Nutrition</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/skincare">Skin Care</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/reviews"><span class="css-1ggvc7">All</span><span class="icon-hl-circle-arrow css-6a6zvz"></span></a><ul><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/reviews/nutrition-products">Nutrition</a></li><li><a class="css-1c2ok3c" href="/cats-d8c4vu/www.healthline.com/sponsored-topics"><span class="css-1ggvc7">All</span><span class="icon-hl-circle-arrow css-6a6zvz"></span></a><ul><li><a class="css-1c2ok3c" href="/cats-d8c4vu/media.post.rvohealth.io/wp-content/uploads/sites/199/2020/06/Mast-Cell-Activation-Syndrome-2-June-2020.pdf">https://med.virginia.edu/ginutrition/wp-content/uploads/2022/01/chicken-rice-vegetable-bowl-732-549-feature-thumb-732x549.jpg 200w" className="css-1lyqwde"></lazy-image></span></span><span class="css-1fb1nmp"><span class="css-a10gts"></span></div></a></figure><div class="css-u8uhak"><a class="css-14kd1uw" rel="nofollow" data-event="engagement|bottom page content promo click|/nutrition/low-fodmap-diet;engagement|bottom page content promo click index|1" data-element-event="INTERNAL LINK|FOOTER|Any Page|Read This Next|LINK|A Beginner’s Guide to the Low FODMAP Diet|rn0" href="/cats-d8c4vu/www.healthline.com/health/hereditary-angioedema/hereditary-angioedema-blood-genetic-tests;engagement|bottom page content promo click index|4" data-element-event="INTERNAL LINK|FOOTER|Any Page|Read This Next|LINK|What to Know About Testing for Hereditary Angioedema|rn3" href="/cats-d8c4vu/media.post.rvohealth.io/wp-content/uploads/2025/10/young-woman-applying-mask-to-face-732x549-thumbnail.jpg" srcSet="https://media.post.rvohealth.io/wp-content/uploads/2022/07/TRUST-Mark-1.png?" className="css-spwcx4"></lazy-image></div></a></div></footer><div id="foot-pad"></div><div id="consent-modal"></div></div><script> HL={"c":{"countryCode":"NZ","countryNumber":554,"continentCode":"OC","stateCode":"AUK","dmaCode":"","SPIConfig":{"default":false,"dcs":false},"consent":{"vendorListTcfVersion":5,"hasGlobalScope":false,"hasFullConsent":false,"hasFullOneTrustConsent":false,"gdprApplies":false,"tcString":false,"pingReturn":{},"shouldUseOT":false,"tcData":{"gdprApplies":false,"cmpLoaded":true,"addtlConsent":"","eventStatus":"cmpuishown"}},"usPrivacyData":{"usprivacy":"1YNY","ccpaApplies":true},"isControl":false,"abSegment":"enableDatadogRUM=false;scrollIndicator=control;adbDlbFix=false;experimentalRPM=variant;adbridgFlag=false;dcsCopayBestOffer=control;dcsNativeCoupon=variant;dcsCopayOnly=variant;adBlockerDetection=false;oneTrustCPRA=true;pathingTest=true;apscustomRemoval=false;showAuth=false;showClusterNavMenu=false;traveler=variant;travelerV2=false;pillIdentifierNoDupes=control;felibQuizMigration=variant;bottomOfArticleRedesign=false;gatedArticle=false;","abId":"f88baf6f-2018-4c42-b903-328de833cde5","isNewId":false,"abTestUrls":{"moveImageGalleryBelowH2":["/health/drugs/trulicity","/health/drugs/spiriva","/health/drugs/januvia","/health/drugs/olumiant","/health/drugs/trintellix","/health/drugs/zetia","/health/drugs/lybalvi","/health/drugs/sunosi","/health/drugs/nplate","/health/drugs/nexplanon","/health/drugs/leqvio","/health/drugs/taltz","/health/drugs/repatha","/health/drugs/venclexta","/health/drugs/nucala"],"prerollAdRule":["/nutrition/9-benefits-oats-oatmeal"],"postrollAdRule":["/health/fitness/weight-bench","/nutrition/best-punching-bag","/nutrition/protein-for-vegans-vegetarians","/nutrition/can-you-drink-rain-water"],"expandedTableOfContents":[],"collapsedTableOfContents":[],"livedExperienceMVP":["/health/regrow-hair-naturally","/health/cold-flu/how-to-get-rid-of-phlegm","/nutrition/6-proven-health-benefits-of-apple-cider-vinegar"],"reducedFontSize":["/health/womens-health/safe-period","/health/shingles-contagious","/nutrition/ginseng-benefits","/health/es/erupcion-cutanea","/health/food-nutrition/best-vitamins-to-take-daily","/nutrition/do-multivitamins-work","/nutrition/pre-workout-supplements","/nutrition/best-cooking-oils","/health/sunscreen-for-oily-skin","/nutrition/best-gluten-free-bread","/health/beauty-skin-care/best-sunscreens-for-dark-skin","/health/best-natural-shampoo","/health/thrive-market-review","/nutrition/best-testosterone-booster-supplements","/health/pregnancy/best-breast-pump","/nutrition/metabolic-renewal-reviews","/nutrition/best-weight-gain-supplements","/nutrition/best-snacks-for-diabetes","/nutrition/best-foods-for-constipation","/health/high-bilirubin","/nutrition/foods-to-avoid-with-kidney-disease-and-diabetes","/health/mental-health/online-sex-therapy","/health/cortisol-tests","/health/everlywell-review","/health/std-treatment-online","/health/best-knee-compression-sleeves","/health/best-stethoscopes","/health/testosterone-test-kits","/health/erectile-dysfunction/medication-list","/health/generic-cialis","/health/4-supplements-as-powerful-as-drugs","/health/decolletage","/health/grounding","/health/beauty-skin-care/nose-pores","/health/how-to-use-kegel-balls","/health/butt-sweat","/health/thinning-hair","/health/boost-your-libido-10-natural-tips","/health/shampoo-seborrheic-dermatitis","/health/fitness-exercise/pool-exercises","/health/broken-tailbone","/health/anxiety/social-anxiety-treatment","/health/beauty-skin-care/how-to-get-rid-of-large-pores","/health/pregnancy/padsicles","/health/low-testosterone/warning-signs","/health/anal-douche","/health/how-to-find-out-your-blood-type","/health/low-porosity-hair"],"moveImageGalleryBelowDeck":["/health/drugs/latuda-dosage","/health/drugs/spiriva-dosage","/health/drugs/rexulti-dosage","/health/drugs/humulin-n-dosage","/health/drugs/provigil-dosage","/health/drugs/cipro-dosage","/health/drugs/entyvio-dosage","/health/drugs/symbicort-dosage","/health/drugs/ajovy-dosage","/health/drugs/vraylar-dosage","/health/drugs/trintellix-dosage","/health/drugs/levemir-dosage","/health/drugs/xarelto-dosage","/health/drugs/ozempic-dosage","/health/drugs/pulmicort-dosage","/health/drugs/rybelsus-dosage","/health/drugs/humalog-dosage","/health/drugs/pristiq-dosage","/health/drugs/viagra-dosage","/health/drugs/cambia-dosage"],"showNonCostJumpLink":["/health/drugs/auvelity-interactions","/health/drugs/auvelity-cost","/health/drugs/auvelity-dosage","/health/drugs/mounjaro-side-effects","/health/drugs/mounjaro-dosage","/health/drugs/mounjaro-interactions","/health/drugs/mounjaro-cost","/health/drugs/nexlizet-cost","/health/drugs/nexlizet-side-effects","/health/drugs/nexlizet-dosage","/health/drugs/otezla-side-effects","/health/drugs/otezla-interactions","/health/drugs/otezla-dosage","/health/drugs/otezla-cost","/health/drugs/rinvoq-side-effects","/health/drugs/rinvoq-cost","/health/drugs/verzenio-side-effects","/health/drugs/verzenio-dosage","/health/drugs/verzenio-cost"],"adSyncFlag":["/health/copd/diet-nutrition","/health/grounding-techniques","/health/how-much-insulin-to-take-chart","/health/lung-cancer/stage-3-symptoms-outlook","/health/photos-types-psoriasis","/health/what-is-memory-care","/health/high-cholesterol/fish-oil-vs-statins"]},"ga":{"k1":"otherskindisorders","k2":"skin","kmeta":"otherskindisorders,mastocytosis,antihistamine,glp-1-predictive-aq-t3","contentType":"Tabbed Article","author":"Nancy Moyer, MD and Erika Klein","articleType":"regular","sponsoredProgramId":"","articleId":"wp-3809380","mainContentCategoryTags":"","publishedDate":"2024-03-26","updatedDate":"2025-04-04","medReviewer":"Alana Biggers, M.D., MPH","category":"Uncategorized","subcategory":"","trackingTerms":"Algo Update","ek1":"2644ced06fdaf994be876f6d69d959f24ca5","ekmeta":"2644ced06fdaf994be876f6d69d959f24ca5,2451d5c172caeb89bf906f6d,285ed2dc75c0e189b18e6f7063,2e5cd6982c84e28fb5876f7d72c24bf213b792c32009,","contentForm":"Head Term","type":"healthfeature"},"adb":false,"d":[],"i":{"enabled":true},"cIds":["e899fe37-d939-4090-8e9d-bb41fc752f22"],"mpd":{"loaded":[{"_driverPath":"/health/mast-cell-activation-syndrome","_contentIndex":"page","driverId":"8632d3ef-99fa-4c6c-918b-b1f4107591db","siteId":"3bd23390-7108-11ea-8600-afc672063050","site":"hl","status":"on","deleted":false,"overridePredictiveRPM":true,"created":"2024-11-12T22:08:30.000Z","updated":"2025-11-13T21:26:53.000Z","createdBy":"liallison@redventures.com","updatedBy":"eprater@rvohealth.com","isTest":true,"overridePredictiveRPMType":"takeover","rewardType":"","customModel":false,"holdout":"","sdapiTestName":"","modelType":"","imageMobile":"https://healthline-activation-prod.healthline.com/driver-images/2ppu%20image%20desktop%20-%20psoriasis.png","confirmCallToActionURL":"https://www.healthline.com/psoriasis?utm_source=hl&utm_medium=confirmation-screen-driver&subid=e%3Acc_s%3Ahl_p%3Anl_n%3Apso_l%3Aheadernewsletter_48329&rvo_sys=mar","secondarySubscriptionSubhead":"Other newsletters you won’t want to miss:","autoOpen":false,"titleOverrideMobile":"Get Our Twice-Weekly Psoriasis Newsletter","feedbackSelections":["Mental Well-Being","Living Well","Remission and Recurrence","Navigating Treatment","Newly Diagnosed","Early Detection"],"secondaryNewsletters":[],"titles":"our popular Heart Health newsletter","descriptionModal":"To help you feel your best, we'll send you lifestyle tips, guidance on dealing with flare-ups, treatment options, and more. ","includeFeedbackStep":true,"driverType":"headerNewsletter","verticalId":"a8cdb235-aa36-4f2d-828e-29662b752c7a","feedbackDescription":"Select as many topics as you'd like, and we'll use this to help personalize future newsletters.","verticalName":"Psoriasis","lists":["Psoriasis"],"confirmCallToAction":"READ MORE","name":"e:cc_s:hl_p:nl_n:pso_l:headernewsletter","imageDesktop":"https://healthline-activation-prod.healthline.com/driver-images/2ppu%20image%20desktop%20-%20psoriasis.png","feedbackTitle":"What topics are you interested in?","style":"standard","descriptionModalMobile":"To help you feel your best, we'll send you lifestyle tips, guidance on dealing with flare-ups, treatment options, and more.","driverPlacementId":"d5b8e667-55c1-4a6d-b05d-728a1733109b","campaignName":"e:cc_s:hl_p:nl_n:pso_l:headernewsletter_48329","productId":"e:cc_s:hl_p:nl_n:pso_l:headernewsletter_48329","_uuid":"mfca46a6d-8187-42df-8043-fbf2041eb4b3mpd_headerNewsletter_8632d3ef-99fa-4c6c-918b-b1f4107591db","cpm":7.630943387350312e+307}],"placed":{},"placements":{},"state":{}},"e":[],"st":{"ddQ":[]},"jwp":{},"m":{"build":"19378321009","version":"39ffba2b7eb062e1ee6c0836ddb6424114ee3dc6","environment":"prod"}}; hlIs=!1; var googletag=googletag||{cmd:[]}; __hlConfig={"adaUrl":"https://t3c55b.enterprise.ada.com","travelerScript":"https://traveler.content.now.optum.com/traveler.umd.js","medchatKey":"EweaRZMhkU-iLMeRSXCoBA","urlPrefix":"www.","absUrl":true,"makeWriteKey":"d2tocF8ydlJsNTJTV0c3SzNSYnFuRXRqR2p5TnFSNko6","hlMakeWriteKey":"d2tfMVRxZjdFWXpPS3l4bTRHdnEwNDJyVTBVa3kwOg==","tagular":{"apiVersion":"v2/t","dailyDose":{"writeKey":"wkhp_30W3Cco2gJdoqgCoSkepDQFwQmf"},"writeKey":"wk_1Tqf7EYzOKyxm4Gvq042rU0Uky0","sourceKey":"src_1Tqf7BF96WTbG5QbUndHWIgKoFo","domainWhitelist":["www.healthline.com","act.healthline.com","frontend-stage.healthline.com","act-stage.healthline.com","activation.healthline.com","activation-stage.healthline.com"],"cookieDomain":"healthline.com","multiparty":true,"reinforce":"https://www.healthline.com/navi","experimentalFeatures":{"flocEnabled":true},"eventSampling":{"eligibleEvents":["DomCompleted","PageScrolled"],"fireRate":25}},"preamp":{"siteId":"2ahYQ7GmZHnMGlBjvg6cFP"},"metricServer":"https://pavlov-prod.healthline.com/","googleRecaptchaSiteKey":"6LcXCYopAAAAAJd3lQzyqu4Q0atIlXh0DRpaJAqn","marketplaceAPI":"https://prepop.healthline.com/export/form-data/","activationHost":"https://activation.healthline.com","datadogRUM":{"applicationId":"512348e0-2b09-41ef-ba89-972c7e598ad8","clientToken":"pub4a8701b4f057fee58e8d2a3dd85184f1"},"gtmServer":"https://gtm-server.healthline.com","gtmConfigValue":"GTM-MB6365D","aimDmdApiKey":"14-51-A5D1AD73","assetsServer":"https://assets.healthline.com","algoliaAppId":"7835BOM3SG","algoliaSearchApiKey":"e34a454de65f33ce5820690f9032bcaf","algoliaSearchIndex":"crawler_Prod Healthline","algoliaQuerySuggestionIndex":"crawler_Prod Healthline_query_suggestions","oneTrustOrgId":"50162747-1340-4ce9-8836-735e1fd65cc6","auth":{"clientId":"b10c0898-6c07-4a01-b977-e5c2f2e7bbf1","customPolicyName":{"apple":"B2C_1A_HEALTHLINE_SIGNUP_SIGNIN_APPLE","google":"B2C_1A_HEALTHLINE_SIGNUP_SIGNIN_GOOGLE"},"authority":"https://login.rvo.health/rvohcentralauthprod.onmicrosoft.com","knownAuthorities":["login.rvo.health"],"scopes":["https://rvohcentralauthprod.onmicrosoft.com/hl-user-profile-api/Profile.ReadWrite"],"healthsafeIdUrl":"https://identity.healthsafe-id.com/web/redirect?to=manage-profile&target=https://www.healthline.com/account/profile","userProfileApiBaseUrl":"https://api.user-profile-prod.healthline.com/api/v1/profile"},"dailyDoseSite":"https://dailydose.healthline.com"}; _comscore=[]; __comscoreParams=[{"c1":"2","c2":"38584006","cs_ucfr":"","cs_fpit":"c","cs_fpdm":"*null","cs_fpdt":"*null","options":{"enableFirstPartyCookie":true,"bypassUserConsentRequirementFor1PCookie":true,"url_append":"comscorekw=main"}}]; function __uspapi(cmd, apiVer, callback) { if (cmd === 'getUSPData') { callback({ version: '1', uspString: __uspapi.d.usprivacy || '1YNY', }, true); } } __uspapi.d = {"usprivacy":"1YNY","ccpaApplies":true}; !function(){if('PerformanceLongTaskTiming' in window){var g=window.__tti={e:[]};g.o=new PerformanceObserver(function(l){g.e=g.e.concat(l.getEntries())});g.o.observe({entryTypes:['longtask']})}}(); function EventListener(eventName, listenerId, data, pingData) { this.eventName = eventName; this.listenerId = listenerId; this.data = data; this.pingData = pingData; } /** * Custom gpc handler for ?isGpc */ const params = new URLSearchParams(document.location.search); if (params.get('isGpc') !== null) { navigator.globalPrivacyControl = true; } /* Cohesion Configs */ function tagular(...args) { tagular.q.push(args); } tagular.q = []; function preamp(...args) { preamp.q.push(args); } preamp.q = []; function cohesion(...args) { cohesion.q.push(args); } cohesion.q = []; const tagularConfigs = {"apiVersion":"v2/t","dailyDose":{"writeKey":"wkhp_30W3Cco2gJdoqgCoSkepDQFwQmf"},"writeKey":"wk_1Tqf7EYzOKyxm4Gvq042rU0Uky0","sourceKey":"src_1Tqf7BF96WTbG5QbUndHWIgKoFo","domainWhitelist":["www.healthline.com","act.healthline.com","frontend-stage.healthline.com","act-stage.healthline.com","activation.healthline.com","activation-stage.healthline.com"],"cookieDomain":"healthline.com","multiparty":true,"reinforce":"https://www.healthline.com/navi","experimentalFeatures":{"flocEnabled":true},"eventSampling":{"eligibleEvents":["DomCompleted","PageScrolled"],"fireRate":25}}; if (HL.i.enabled) { /* Only suppress some tagular events for infinite scroll */ Object.assign(tagularConfigs, { beamHook(event) { /* Executed every time beam is called and passed the event */ /* eslint-disable-next-line no-underscore-dangle */ window._Tagular.config.suppressBeam = event['@type'] === 'redventures.usertracking.v3.PageScrolled'; } }) } const preampConfigs = HL.ga.contentType === 'brand-page' ? false : { ...{"siteId":"2ahYQ7GmZHnMGlBjvg6cFP"}, hooks: { /* Runs before Preamp requests a new decision */ beforeRun(cohesionConfig, done) { /* Adds k1 to custom Preamp values */ /* Allows Preamp experiences to be created based on the current K1 */ cohesionConfig.custom = { ...cohesionConfig.custom, k1: HL.ga.k1, }; done(); }, beforePlacement(placement, done) { const interval = setInterval(() => { if (window.afterMPD) { /* Defer preamp rendering until we have injected all MPDs as those */ /* need to be in the DOM for Preamp to inject into. */ afterMPD(done); clearInterval(interval); } },500) }, } }; /* eslint-disable-next-line no-underscore-dangle */ window._Cohesion = { k: 'cohesion', tagular: tagularConfigs, preamp: preampConfigs }; window._Tagular = { k: 'tagular' }; window._Preamp = { k: 'preamp', start: new Date(), docReady: true }; window._Fuse = { k: 'fuse', docReady: false }; window.tagular = tagular; window.preamp = preamp; window.fuse = () => {}; window.cohesion = cohesion; </script><script> var AdBridg = AdBridg || {cmd: []}; </script><script id="ad-bridg-mounted" src="/cats-d8c4vu/pub.doubleverify.com/dvtag/20447058/DV1208979/pub.js" async=""></script><script> var skimlinks_settings = { skimlinks_exclude: ['www.amazon.com', 'amazon.com', 'amzn.to'] }; </script><script src="/cats-d8c4vu/client.aps.amazon-adsystem.com/publisher.js" as="script" fetchpriority="high"/><script src="/cats-d8c4vu/assets.healthline.com/_next/felib-cc885.js" crossorigin="anonymous" async=""></script><script type="module" src="/cats-d8c4vu/assets.healthline.com/_next/d6731c89-f665-4960-8415-4a4f1995315c/hl/pages/infinite.js" crossorigin="anonymous" async=""></script><div> <script type="application/ld+json">{"@context":"https://schema.org","publisher":{"@type":"Organization","name":"Healthline Media","logo":{"@type":"ImageObject","url":"https://media.post.rvohealth.io/wp-content/uploads/2022/07/female-scratching-arm-732-549-feature-thumb-732x549.jpg"]}</script><script type="application/ld+json">{"@type":"MedicalCondition","@context":"https://schema.org","url":"https://www.healthline.com/health/mast-cell-activation-syndrome/","name":"Mast Cell Activation Syndrome (MCAS)","description":"A condition that occurs when the mast cells in your body release too much of a substance that causes allergy-like symptoms.","signOrSymptom":["Running nose","Headache","Nausea","Sweating","Fatigue","Inflammation","Diarrhea","Itching mouth and throat","Rapid heart rate","Anaphylactic shock","Itching","Mucus","Flushing","Hives","Swelling","Rash","Irritation","Watering eyes","Itching nose","Swelling in tongue or lips","Swelling in throat","Trouble breathing","Wheezing","Low blood pressure","Cramping","Abdominal pain","Confusion"]}</script></div><noscript><img alt="" src="/cats-d8c4vu/b.scorecardresearch.com/p?c1=2&c2=38584006&cv=3.9&cj=1&comscorekw=main" loading="eager"/>

Follow Lee on X/Twitter - Father, Husband, Serial builder creating AI, crypto, games & web tools. We are friends :) AI Will Come To Life!

Check out: eBank.nz (Art Generator) | Netwrck.com (AI Tools) | Text-Generator.io (AI API) | BitBank.nz (Crypto AI) | ReadingTime (Kids Reading) | RewordGame | BigMultiplayerChess | WebFiddle | How.nz | Helix AI Assistant